Apparatuses and methods consistent with exemplary embodiments described in the present disclosure relate to a substrate separation device and a substrate separation system.
A laser lift-off (LLO) method is largely used in separating a growth substrate in a process of manufacturing a vertical type light emitting diode (LED). The LLO method is a technique of growing semiconductor epitaxial layers on a growth substrate, bonding a support substrate to an uppermost semiconductor epitaxial layer, and subsequently irradiating a laser beam through the growth substrate to separate the growth substrate from the epitaxial layers.
Here, after bonding the support substrate, bowing may occur due to a difference in coefficients of thermal expansion between the growth substrate and the support substrate. In this case, a focal point of a laser beam may be changed, leading to a failure to transmit energy to an interface between the growth substrate and the epitaxial layers accurately, thereby failing to properly separate the growth substrate.
Failure of transmission of a laser beam due to a defect in the growth substrate, deposition of a metal thin film, contamination, or the like, causes an epitaxial layer or a buffer layer to partially remain, which may damage the growth substrate or the support substrate in the process of separating the growth substrate.